IntermediateBEHAVIORAL
Tell me about a time you identified a data-related bottleneck or quality issue in a business process. How did you uncover it, what analysis did you perform, and what measurable improvement resulted from your solution?
Data Analyst
General

Sample Answer

In my last role, our weekly sales forecast was always late and constantly revised. On paper, the process was fine, but cycle time was 3+ days and accuracy hovered around 70%. I started by mapping the end-to-end data flow and logging timestamps at each handoff. The logs showed 60% of the delay came from manual Excel reconciliations due to mismatched customer IDs between CRM and billing. I pulled a month of data, profiled key fields, and found about 12% of records had inconsistent IDs or naming conventions. I built a Python-based matching script using fuzzy joins and a reference mapping table, then moved the reconciliation into a scheduled SQL job. We also added simple validation checks (missing IDs, duplicate invoices) and a daily data-quality report to Slack. Forecast prep time dropped from 3 days to under 8 hours, and forecast accuracy improved from ~70% to 88% over the next quarter. Finance highlighted it as a key reason they could lock the forecast a day earlier.

Keywords

Mapped the full process and quantified delays with timestamps and logsUsed data profiling to identify inconsistent IDs as the core quality issueImplemented Python matching logic and scheduled SQL jobs to automate reconciliationReduced cycle time by ~70% and improved forecast accuracy by ~18 percentage points